Job stress is a pervasive problem for employers in the 21st century economy, making it a timely and important topic in organizational settings. The variables influencing job stress are numerous and consequently it may be analyzed from different perspectives, but the root is primarily physical and psychosocial. This study specifically explores three physical sources of job stress—contractual condition of work, organizational position, and dimension of organization—and of one psychosocial source—work conflict. A survey instrument was used to collect information from regional Public Administration employees of South Italy. Data from 1,130 respondents were analyzed. Statistical correlations and hierarchical regression showed that contractual condition of work, organizational position, organizational dimension, and work conflict were all predictive aspects of job stress.